DISCUSSION
DEB is an autosomal dominant or recessive genodermatosis caused by
variations in COL7A1. Its pathogenesis is not completely understood. EBP
is characterized by nodular prurigo-like lichenoid lesions with intense
itching, in addition to the features of DEB, such as blisters and
onychodystrophy. 1 Currently, EBP is treated with
topical corticosteroids, tacrolimus, and oral thalidomide, but the
outcomes are often unsatisfactory.2-3 Baricitinib is a
reversible selective inhibitor of tyrosine protein kinase, which is
capable of modulating the signal transduction of helper T-cells (Th1,
Th2, Th17, and Th22) and participates in many immune-mediated disorders.
Here, one case of baricitinib in the treatment of EBP was discussed.
This case clinically presented with dense nodular, keratotic papules,
mainly on the extensor side of both lower limbs, which were brownish in
color, with umbilical concavity at the center of some of them, and
subepidermal blisters could be seen by the results of the examination,
while there were no obvious eosinophils in the blisters, and there was
mixed inflammatory cell infiltration in the dermis, so we considered
this to be a case of a specific type, Epidermolysis Bullosa
Pruriginosa. Janus kinase-signal
transducer and activator of transcription (JAK-STAT) is an intracellular
signaling pathway upon which many different proinflammatory signaling
pathways converge. Numerous inflammatory dermatoses are driven by
soluble inflammatory mediators, which rely on JAK-STAT signaling, and
inhibition of this pathway using JAK inhibitors might be a useful
therapeutic strategy for these diseases. Evidence suggests that the
dysregulation of helper T-cell (Th1, Th2, and Th17) signal transduction
is implicated in epidermolysis bullosa. Chronic inflammation is a
hallmark of DEB, thus upregulation of inflammatory cytokines and JAK
signaling may play a role in DEB-related pruritus. Caroppo reported one
case of EBP who was successfully treated with dupilumab. Dupilumab can
dually block and inhibit both IL-4 and IL-13 and suppress Th2-mediated
inflammatory responses, thus significantly improving skin lesions and
relieving itching.4 This suggests that EBP may be
triggered by Th2 immune mechanisms. In addition, it was reported that
baricitinib could alleviate itching associated with AD, and the
significant relief of itching proves the effectiveness of this strategy,
which is the rationale behind the application of baricitinib in our
hospital for targeted treatment through its downstream JAK-STAT signal.
JAK may be a favored target for EBP-associated symptoms. Moreover,
considering the affordability and durability of the treatment regimen
for patients, baricitinib has become the preferred treatment choice in
our clinic instead of dupilumab. Jiang XY et al. reported one case of
EBP in a 40-year-old man without a family history of DEB and with severe
skin lesions and intense itching, which is significantly improved after
treatment with baricitinib. 5 He was followed up once
every 2 weeks until 16 weeks, and then every 8 weeks. The scores of all
three indicators decreased over time. Joo Kwon retrospectively reviewed
the medical records of DEB patients with refractory pruritus who were
treated with either baricitinib, a JAK1/2 inhibitor, or upadacitinib, a
selective JAK1 inhibitor. A total of 12 DEB patients (six recessive DEB
and six dominant DEB) were included in this study. The mean±SD baseline
pruritus visual analog scale score was 7.5 ± 1.7. Upadacitinib or
baricitinib treatment resulted in a rapid and sustained decrease in
itch.6
In this paper, one case of EBP was discussed. The patient had a long
history of EBP and a relevant family history of the disease. The typical
skin lesions initially manifested as multiple lichenoid papules and
nodules on both lower extremities, especially their extensor aspect,
with scars forming in the center of the larger nodules, accompanied by
mild scale. Combined with the fact that the results of previous
examinations, the herpetic autoantibody test, and other examinations
were all negative, prurigo nodularis and herpes could be excluded. The
patient had intense itching, which is one of the important
manifestations of EBP. The patient had received traditional treatment
for more than 10 years, and while the progression of the disease had
been controlled to a certain extent, the outcome of itching relief was
unsatisfactory. The patient was treated with baricitinib in our hospital
with the hope of relieving the itching. During the 2 years of treatment
with baricitinib, the patient’s skin rashes had subsided and flattened
significantly, and his itching was markedly relieved. The VAS itching
score of the patient was assessed at follow-up, and the point plot
showed that the score had gradually declined from 8–9 points to 2–3
points, indicating a greatly improved quality of life.
EBP is a persistent, recurring disease that seriously affects quality of
life. this study confirms that baricitinib is effective and feasible in
treating EBP, especially in significantly relieving itching, which
rendered new ideas for therapeutic approaches for EBP in the future.
Particularly important for patients suffering from severe itchiness.